A diode is an electrical device allowing current to move through it in one direction with far greater ease than in the other. The most common kind of diode in modern circuit design is the semiconductor diode.
Examples of the semiconductor diode include a shallow trench isolation (STI) diode and a gated diode. Both of these types of diodes generally have fast turn-on times and high conductance, which makes them well-suited for electro-static discharge (ESD) protection circuits.
In some cases, the gated diode may be formed using a fin field-effect transistors (FinFET) process. FinFETs have allowed the semiconductor industry to continue shrinking the size and increasing the speed of individual FETs. Indeed, FinFETs or multiple gate transistors may be used in sub 32 nm transistor nodes. FinFETs not only improve areal density but also improve gate control of the channel.
Unfortunately, both gated diodes and STI diodes may suffer from undesirable drawbacks.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.